Electronic parking brake actuation device

Abstract

This utility model discloses an electronic parking brake actuator, comprising a gearbox, a primary gear transmission assembly, and a secondary gear transmission assembly. The gearbox includes an upper housing and a lower housing. The upper housing has a first positioning groove and a second positioning groove, and the lower housing has a third positioning groove. The primary gear transmission assembly includes a first gear, a second gear, and a positioning shaft coaxially arranged. The positioning shaft passes through the first positioning shaft hole and the second positioning shaft hole, and includes a first end and a second end. The first end is fixed at the first positioning groove, and the second end is fixed at the third positioning groove. The secondary gear transmission assembly includes a third gear, a sun gear, and a positioning ring coaxially arranged. The sun gear and the positioning ring are integrally injection molded, the third gear is fixedly connected to the sun gear, and the positioning ring is disposed in the second positioning groove. This utility model can improve the strength and durability of the gear transmission mechanism.

Description

Technical Field

[0001] This utility model relates to the field of automotive parts, and in particular to an electronic parking brake actuator. Background Technology

[0002] Electronic parking brake actuators typically include a gear transmission mechanism as a core safety component, the performance of which directly affects the reliability of the vehicle's braking system. The gear transmission mechanism is used to convert the rotational motion of the motor into the clamping force of the brake caliper, that is, to convert the motor's rotational motion into linear motion, pushing the brake pads to clamp the brake disc, thereby achieving static locking and dynamic emergency braking of the vehicle.

[0003] A good gear transmission mechanism needs to have high strength and durability. Currently, the positioning shaft material of most gear transmission mechanism products on the market is plastic, which has relatively weak strength. In addition, gear transmission mechanism products mostly use press-fitting process to fix related parts, which has low production efficiency. After long-term use, the parts may loosen, which may cause safety hazards. Utility Model Content

[0004] The purpose of this invention is to solve the problems of weak strength and poor durability of gear transmission mechanisms. This invention provides an electronic parking brake actuator that can improve the strength and durability of gear transmission mechanisms.

[0005] To solve the above-mentioned technical problems, the present invention discloses an electronic parking brake actuator, comprising: a gearbox housing, the gearbox housing including an upper housing and a lower housing, the upper housing having a first positioning groove and a second positioning groove, and the lower housing having a third positioning groove; a primary gear transmission assembly including a first gear, a second gear, and a positioning shaft coaxially arranged, the first gear having a first positioning shaft hole, the second gear having a second positioning shaft hole, the first positioning shaft hole and the second positioning shaft hole communicating with each other, the positioning shaft passing through the first positioning shaft hole and the second positioning shaft hole, the positioning shaft including a first end and a second end, the first end being fixed at the first positioning groove, and the second end being fixed at the third positioning groove; and a secondary gear transmission assembly including a third gear, a sun gear, and a positioning ring coaxially arranged, the sun gear and the positioning ring being integrally injection molded, the third gear being fixedly connected to the sun gear, the third gear meshing with the second gear, and the positioning ring being disposed at the second positioning groove.

[0006] Using the above technical solution, the upper housing and the lower housing are respectively provided with a first positioning groove, a second positioning groove and a third positioning groove. The first end of the positioning shaft is positioned through the first positioning groove, and the second end of the positioning shaft is positioned through the third positioning groove. The positioning shaft passes through the first positioning shaft hole and the second positioning shaft hole, thereby positioning the positions of the first gear and the second gear. Compared with the structure without a positioning shaft, by setting the positioning shaft, the radial and axial positioning of the first gear transmission assembly can be ensured, which can effectively suppress the vibration generated by the first gear and the second gear during rotation, thereby improving the stability of the transmission.

[0007] Similarly, the positioning ring is positioned by the second positioning groove. After the sun gear is integrally injection molded with the positioning ring, the third gear is then fixedly connected to the sun gear. In other words, the two-stage transmission gear assembly is set as a whole structure. While being positioned by the positioning ring, the strength and durability of the positioning ring can be increased.

[0008] According to another specific embodiment of this utility model, the sun gear and the positioning ring are made of metal materials.

[0009] Using the above technical solution, comparing plastic positioning rings, metal positioning rings can effectively increase the strength of the positioning rings.

[0010] According to another specific embodiment of the present invention, the sun gear includes a bearing portion and a gear portion, and the bearing portion is fixed to the third gear by means of plastic coating.

[0011] Using the above technical solution, the third gear is fixed to the bearing part by plastic coating, that is, the third gear is fixed to the sun gear by a secondary injection molding process, which makes the power transmission more synchronized and can improve the integrity and stability of the two-stage gear transmission assembly.

[0012] According to another specific embodiment of the present invention, the positioning shaft is encased in the third positioning groove.

[0013] Compared with the press-fitting process, the positioning shaft is fixed in the third positioning groove by plastic coating, which means that the positioning shaft and the lower housing are integrally formed by secondary injection molding. This saves the press-fitting process and can effectively improve the bonding strength between the positioning shaft and the lower housing, avoid the loosening problem that may be caused by press-fitting, and improve its durability.

[0014] According to another specific embodiment of the present invention, the positioning shaft is a smooth cylinder.

[0015] According to another specific embodiment of the present invention, the circumferential surface of the positioning shaft is provided with a first groove, and the first groove is disposed in the third positioning groove.

[0016] By adopting the above technical solution, the first groove allows molten plastic to fill the first groove when the positioning shaft and the third positioning groove are fixed by plastic coating, thereby increasing the contact area between the molten plastic and the positioning shaft. Subsequently, by cooling and fixing, an interlocking mechanical connection is formed, thereby enhancing the stability of the positioning shaft.

[0017] According to another specific embodiment of the present invention, the circumferential surface of the positioning shaft is provided with a second groove, the second groove and the first groove are symmetrically arranged at both ends of the positioning shaft along a first axis, and the first axis is arranged perpendicular to the axial direction of the first gear.

[0018] By adopting the above technical solution, the first groove and the second groove symmetrically arranged at both ends of the circumferential surface of the positioning shaft can play a role in preventing errors during assembly and saving assembly time.

[0019] According to another specific embodiment of the present invention, the circumferential surface of the positioning shaft has an uneven structure.

[0020] By adopting the above technical solution, by adding an uneven structure to the circumferential surface of the positioning shaft, when the positioning shaft and the third positioning groove are fixed by plastic coating, the molten plastic can fill the groove, thereby increasing the contact area between the molten plastic and the positioning shaft. Subsequently, by cooling and fixing, an interlocking mechanical connection is formed, thereby enhancing the stability of the positioning shaft.

[0021] According to another specific embodiment of the present invention, the circumferential surface of the positioning shaft has a knurled structure.

[0022] According to another specific embodiment of the present invention, the first gear and the second gear are integrally injection molded.

[0023] By adopting the above technical solution, the first gear and the second gear can be directly injection molded together, which can reduce unnecessary connecting parts and improve the strength and rotational accuracy of the first-stage gear transmission assembly. Attached Figure Description

[0024] Figure 1 An exploded view of the electronic parking brake actuator of this utility model is shown;

[0025] Figure 2 A cross-sectional view of the electronic parking brake actuator of this utility model is shown;

[0026] Figure 3 A perspective view of the first-stage gear transmission assembly is shown, in which the locating shaft is not shown;

[0027] Figure 4 A top view of the first-stage gear transmission assembly is shown, in which the locating shaft is not shown;

[0028] Figure 5 It shows Figure 4 The diagram shows a cross-sectional view of the first-stage gear transmission assembly along the CC direction, where the locating shaft is not shown.

[0029] Figure 6 A perspective view of the two-stage gear transmission assembly is shown;

[0030] Figure 7 A top view of the two-stage gear transmission assembly is shown;

[0031] Figure 8 It shows Figure 7 The cross-sectional view of the two-stage gear transmission assembly shown is along the DD direction;

[0032] Figure 9 Side views of the positioning axis are shown in different embodiments, wherein, Figure 9 In the middle (a), it is indicated that the positioning axis is a smooth cylinder. Figure 9 (b) indicates that the circumferential surface of the positioning shaft has a first groove. Figure 9 (c) indicates that the circumferential surface of the positioning shaft has a second groove, which is symmetrically arranged with the first groove at both ends of the positioning shaft along the first axis. Figure 9 In the middle (d), it indicates that the circumferential surface of the positioning shaft has a knurled structure. Detailed Implementation

[0033] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. Although the description of this utility model will be presented in conjunction with preferred embodiments, this does not mean that the features of this utility model are limited to this embodiment. On the contrary, the purpose of describing the utility model in conjunction with the embodiments is to cover other options or modifications that may be derived based on the claims of this utility model. To provide a deep understanding of this utility model, many specific details will be included in the following description. This utility model may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of this utility model, some specific details will be omitted in the description. It should be noted that, without conflict, the embodiments and features in the embodiments of this utility model can be combined with each other.

[0034] It should be noted that in this specification, similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0035] In the description of this embodiment, it should be noted that the terms "upper", "lower", "inner", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the utility model product is usually placed in during use. They are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the utility model.

[0036] The terms “first”, “second”, etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0037] In the description of this embodiment, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set up," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment based on the specific circumstances.

[0038] To make the objectives, technical solutions, and advantages of this utility model clearer, the embodiments of this utility model will be described in further detail below with reference to the accompanying drawings.

[0039] Electronic parking brake actuators typically include a gear transmission mechanism as a core safety component, the performance of which directly affects the reliability of the vehicle's braking system. The gear transmission mechanism is generally used to convert the rotational motion of the motor into the clamping force of the brake caliper. However, in some existing embodiments, the positioning shaft is often made of plastic, which has relatively low strength and transmission efficiency. Furthermore, gear transmission mechanism products often use press-fitting processes to fix related components, resulting in low production efficiency. Prolonged use may lead to loosening of components, potentially causing safety hazards.

[0040] Therefore, this application provides an electronic parking brake actuator, wherein the sun gear and the positioning ring of the electronic parking brake actuator are integrally injection molded, and the positioning shaft is fixed to the lower housing through a plastic coating process, thereby enhancing the strength of the gear transmission mechanism and improving its durability.

[0041] refer to Figure 1 and Figure 2The electronic parking brake actuator 100 of this application embodiment includes a gearbox 200, a primary gear transmission assembly 300, a secondary gear transmission assembly 400, a motor 110, and a planetary gear assembly 120. The gearbox 200 includes an upper housing 210 and a lower housing 220. The upper housing 210 has a first positioning groove 211 and a second positioning groove 212, and the lower housing 220 has a third positioning groove 221. The primary gear transmission assembly 300 includes a first gear 310, a second gear 320, and a positioning shaft 330 arranged coaxially. The secondary gear transmission assembly 400 includes a third gear 410, a sun gear 420, and a positioning ring 430 arranged coaxially. The motor 110 has a motor output shaft gear 111 at its end.

[0042] It should be noted that the motor output shaft gear 111 meshes with the first gear 310 to drive the first gear 310 to rotate. The first gear 310 and the second gear 320 are coaxially arranged and integrally injection molded. That is, when the first gear 310 rotates, the second gear 320 rotates synchronously. At the same time, the third gear 410 meshes with the second gear 320. When the second gear 320 rotates, it drives the third gear 410 to rotate. The third gear 410 is integrally arranged with the sun gear 420. That is, when the third gear 410 rotates, the sun gear 420 rotates synchronously. At the same time, the sun gear 420 meshes with the planetary gear assembly 120 and synchronously drives the planetary gear assembly 120 to rotate.

[0043] In this embodiment, the first gear 310, the second gear 320, and the third gear 410 are plastic parts, while the sun gear 420 and the positioning ring 430 are made of powder metallurgy iron-based material. However, those skilled in the art will understand that in other embodiments, the first gear 310, the second gear 320, and the third gear 410 may also be made of metal, such as aluminum, steel, or copper, and the sun gear 420 and the positioning ring 430 may also be made of other metal materials, such as aluminum, steel, or copper.

[0044] Further, refer to Figures 2 to 5 In the first-stage gear transmission assembly 300, the first gear 310 and the second gear 320 are integrally injection molded. The first gear 310 is provided with a first positioning shaft hole 311, and the second gear 320 is provided with a second positioning shaft hole 321. The first positioning shaft hole 311 and the second positioning shaft hole 321 are connected. The positioning shaft 330 passes through the first positioning shaft hole 311 and the second positioning shaft hole 321. The positioning shaft 330 includes a first end 331 and a second end 332. The first end 331 is fixed at the first positioning groove 211, and the second end 332 is fixed at the third positioning groove 221. The positioning shaft 330 is encased in the third positioning groove 221.

[0045] Specifically, the upper housing 210 and the lower housing 220 are respectively provided with a first positioning groove 211 and a third positioning groove 221. The first end 331 of the positioning shaft 330 is positioned through the first positioning groove 211, and the second end 332 of the positioning shaft 330 is positioned through the third positioning groove 221. The positioning shaft 330 passes through the first positioning shaft hole 311 and the second positioning shaft hole 321, thereby positioning the positions of the first gear 310 and the second gear 320. At the same time, the positioning shaft 330 is fixed in the third positioning groove 221 by plastic coating.

[0046] On the other hand, compared with the structure without a positioning shaft, the positioning shaft 330 can ensure the radial and axial positioning of the first-stage gear transmission assembly 300, effectively suppressing the vibration generated by the first gear 310 and the second gear 320 during rotation, thereby improving the stability of the transmission. Furthermore, compared with the press-fitting process, the positioning shaft 330 is fixed in the third positioning groove 221 by plastic coating, that is, the positioning shaft 330 and the lower housing 220 are integrally formed by secondary injection molding. While saving the press-fitting process, it can effectively improve the bonding strength between the positioning shaft 330 and the lower housing 220, avoid the loosening problem that may be caused by press-fitting, and improve its durability.

[0047] For example, the first end 331 of the positioning shaft 330 is clearance-fitted with the first positioning groove 211.

[0048] refer to Figure 2 , Figures 6 to 8 In the two-stage gear transmission assembly 400, the sun gear 420 and the positioning ring 430 are integrally injection molded. The third gear 410 is fixedly connected to the sun gear 420 and meshes with the second gear 320. The sun gear 420 includes a bearing part 421 and a gear part 422. The bearing part 421 and the third gear 410 are fixed by plastic coating. The first gear 310 has a first central axis A, and the third gear 410 has a second central axis B. The first central axis A and the second central axis B are arranged parallel to each other. The positioning ring 430 is set at the second positioning groove 212.

[0049] In this embodiment, the bearing portion 421, the gear portion 422, and the positioning ring 430 are first integrally injection molded, thereby increasing the strength and durability of the positioning ring 430. Subsequently, the bearing portion 421 and the third gear 410 are fixed by plastic coating. That is, the secondary gear transmission assembly 400 is a single integrated structure, which makes the power transmission more synchronized and improves the overall integrity and stability of the secondary gear transmission assembly 400. At the same time, the positioning ring 430 is positioned by the second positioning groove 212. However, those skilled in the art will understand that in other embodiments, the bearing portion 421 and the third gear 410 can be fixed by other means, such as integral injection molding or interference fitting.

[0050] For example, the positioning ring 430 is clearance-fitted with the second positioning groove 212.

[0051] For example, the sun gear 420 and the positioning ring 430 are integrally stamped into a single part using powder metallurgy molds. However, those skilled in the art will understand that in other embodiments, the sun gear 420 and the positioning ring 430 can be integrally injection molded by other means, such as powder forging.

[0052] refer to Figure 2 as well as Figure 9 In (a), the positioning axis 330 is a smooth cylinder.

[0053] In some possible implementations, refer to Figure 9 In (b), the circumferential surface of the positioning shaft 330 is provided with a first groove 333, which is located in the third positioning groove 221.

[0054] Specifically, the first groove 333 allows the molten plastic to fill the first groove 333 when the positioning shaft 330 and the third positioning groove 221 are fixed by plastic coating, thereby increasing the contact area between the molten plastic and the positioning shaft 330. Subsequently, through cooling and fixing, an interlocking mechanical connection is formed, thereby more firmly fixing the positioning shaft 330 in the third positioning groove 221 by plastic coating, so as to enhance the stability of the positioning shaft.

[0055] For example, a first groove 333 is provided on the circumferential surface of the positioning shaft 330 within the first positioning groove 211. However, those skilled in the art will understand that in other embodiments, the circumferential surface of the positioning shaft 330 may be provided with several grooves within the first positioning groove 211, and this application does not limit this.

[0056] In some possible implementations, refer to Figure 9 In section (c), a second groove 334 is provided on the circumferential surface of the positioning shaft 330. The second groove 334 and the first groove 333' are symmetrically arranged at both ends of the positioning shaft 330 along the first axis X. The first axis X is perpendicular to the first central axis A and the second central axis B, respectively (e.g., Figure 2 (As shown).

[0057] For example, a pair of grooves are symmetrically arranged at both ends of the positioning shaft 330 along the first axis X. However, those skilled in the art will understand that in other embodiments, several pairs of grooves may be symmetrically arranged at both ends of the positioning shaft 330 along the first axis X, and this application does not limit this.

[0058] In some possible implementations, refer to Figure 9 In the middle (d), the circumferential surface of the positioning shaft 330 has an uneven structure.

[0059] Specifically, by adding an uneven structure to the circumferential surface of the positioning shaft 330 to increase friction, the positioning shaft 330 is more firmly fixed in the third positioning groove 221 by plastic coating.

[0060] For example, the circumferential surface of the positioning shaft 330 has a knurled structure. However, those skilled in the art will understand that in other embodiments, the circumferential surface of the positioning shaft 330 may also have other uneven structures, such as threaded structures, ball bearing recess structures, etc.

[0061] Although the present invention has been illustrated and described with reference to certain preferred embodiments, those skilled in the art should understand that the above description is a further detailed explanation of the present invention in conjunction with specific embodiments, and should not be construed as limiting the specific implementation of the present invention to these descriptions. Those skilled in the art can make various changes in form and detail, including some simple deductions or substitutions, without departing from the spirit and scope of the present invention.

Claims

1. An electronic parking brake actuator, characterized in that, include: A gearbox housing, comprising an upper housing and a lower housing, wherein the upper housing is provided with a first positioning groove and a second positioning groove, and the lower housing is provided with a third positioning groove; A single-stage gear transmission assembly includes a first gear, a second gear, and a positioning shaft arranged coaxially. The first gear has a first positioning shaft hole, and the second gear has a second positioning shaft hole. The first positioning shaft hole and the second positioning shaft hole are connected. The positioning shaft passes through the first positioning shaft hole and the second positioning shaft hole. The positioning shaft includes a first end and a second end. The first end is fixed at the first positioning groove, and the second end is fixed at the third positioning groove. The two-stage gear transmission assembly includes a third gear, a sun gear, and a positioning ring arranged coaxially. The sun gear and the positioning ring are integrally injection molded. The third gear is fixedly connected to the sun gear and meshes with the second gear. The positioning ring is disposed at the second positioning groove.

2. The electronic parking brake actuator as described in claim 1, characterized in that, The sun gear and the positioning ring are made of metal.

3. The electronic parking brake actuator as described in claim 1, characterized in that, The sun gear includes a bearing portion and a gear portion, and the bearing portion is fixed to the third gear by plastic coating.

4. The electronic parking brake actuator as described in claim 3, characterized in that, The positioning shaft is encased in the third positioning groove.

5. The electronic parking brake actuator as described in claim 4, characterized in that, The positioning shaft is a smooth cylinder.

6. The electronic parking brake actuator as described in claim 5, characterized in that, The circumferential surface of the positioning shaft is provided with a first groove, which is disposed within the third positioning groove.

7. The electronic parking brake actuator as described in claim 6, characterized in that, The circumferential surface of the positioning shaft is provided with a second groove, which is symmetrically arranged with the first groove at both ends of the positioning shaft along the first axis. The first axis is perpendicular to the axial direction of the first gear.

8. The electronic parking brake actuator as described in claim 4, characterized in that, The circumferential surface of the positioning shaft has an uneven structure.

9. The electronic parking brake actuator as described in claim 8, characterized in that, The circumferential surface of the positioning shaft has a knurled structure.

10. The electronic parking brake actuator as described in claim 1, characterized in that, The first gear and the second gear are integrally injection molded.

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